If you don’t recognize the word already, you’ll smell it the second you do.

It’s the smell that comes when there’s rain after a dry spell.

The word comes the combination of the Greek word for “stone” and for “the blood of the gods” (“petri” and “ichor,” respectively).

And it fits.

What amazes me is that petrichor is both so similar and so different. It varies quite distinctly depending on where you are — and yet it, one of the great gifts of the heat of summer, is immediately and constantly recognizable.

In the foothills of the Rocky Mountains, the damp of sudden rain mixes with the earthy must of the lodgepole pines and rises full and rich from the ground, so thick it feels like you should be tasting it instead of smelling it.

On woods trails in the Atlantic provinces, the distinctive top note comes from the suddenly soaked and breathing peat and mosses. On the Newfoundland barrens it is a long, damp exhalation of ground juniper and all the other bog plants, opening pores and throwing caution, and their perfume, to the winds.

Higher in the Rockies, it’s best when it comes with the excited late spring burst of all the wildflowers at once. In Manitoba, its magic comes on foot with wet hot dirt roads at night, the way your nose is no longer blocked with the dry road dust but instead, you feel as if your lungs and sinuses have grown two sizes, all the better to haul in the great perfumed wonder of prairie thunderstorms. (With the bonus of thunder, you even get to have a hint of the smell early, before the drops even start to fall.)

On the Newfoundland barrens it is a long, damp exhalation of ground juniper and all the other bog plants, opening pores and throwing caution, and their perfume, to the winds.

It’s all helped, of course, by the fact that the humidity makes your nose more sensitive. (The trick is that the droplets in water vapour deliver the scent to your nose.)

You know it immediately — it transports you. Back in time, and sometimes, in place.

Now, here’s a test. Maybe you can remember the last few times you smelled it — I do, but only because I made a point of doing it.

Two weeks ago, with the weather walking back and forth across the line between sun and rain, I had it catch me on an alder-hemmed abandoned railway line surrounding by acres of wild rambling pink roses. Then a week later, coming down a hill trail from work, I was caught by a fast-moving shower that made its own mist, that washed over me and kept going, faster than I could walk. And I caught the whole of it, the smells just exploding up from the ground like they’d been waiting for days to make their escape.

Like a combination of both spruce needles and chanterelles, crushed together under my nose, along with the compost of black rich soil, wet rotting bark and the delicious decay of the world’s full cycle. I stopped and watched the sun come back out, the shower marching away across the valley filled with city, the wet rocks of the path shiny at first and then fading to dull as the water wicked away into the air again, the trees dripping their randomly shed drops.

It was like hearing an orchestra. No, it was like standing in the middle of an orchestra as it played on all sides of you.

If you remember the last time you smelled it, try, just try, to remember exactly how it smelled.

That’s the hard part.

Or, you can do what I do; wait, and hope to be able to stop what you’re doing and smell all of it again.